1. Field of the Invention
The present invention relates to technology for implementing a variety of cooperative processes through cooperative operation of various types of processors residing on a network, and more particularly to security technology in cooperative processes.
2. Description of the Related Art
There is suggested a workflow system, in which devices, such as a scanner, a fax machine, a printer, a copier, and a multifunction machine in which functions of those devices are integrated, are connected to a LAN (Local Area Network) so as to allow the devices to cooperate with an information processor such as a personal computer, and a mail server, for providing various services supporting office work.
Further, technology for making various types of web applications scattered across the Internet cooperate with each other has been suggested in recent years. Because a system configured by linking application services provided by a wide variety of suppliers on the Internet allows a user to utilize a variety of existing services, the widespread expectation is that the system will bring about significant reduction in cost associated with system development. Attention is also being given to languages such as XML (extensible Markup Language) as common ground on which to implement cooperative services.
As a conventional workflow system, those described in Japanese Patent Laid-Open Publication No. Hei 08-123744, No. 2002-099686, and No. 2001-282970 are known.
In the workflow system, it is necessary to transmit instruction data, representing a process to be executed by each processor, to the corresponding processor for implemention of a cooperative service. When a workflow is constructed through the use of a processor provided on the Internet, instruction data directed toward the processor would be transmitted over the Internet. However, in a conventional workflow system, consideration is not given to security of such instruction data transmitted over a network.
On the other hand, as the way in which instruction data is supplied to a plurality of processors which cooperatively operate in the cooperative service, for example, it is considered that the instruction data to be supplied to all the processors is written in a single instruction form and the instruction form is sent to all the processors. In this manner, the instruction data specifically directed toward a certain processor would also be transmitted to other processors. This method provides little problem as long as all the processors reside in a network organized in the same company, while in this method, the instruction data directed toward a processor in a company may be leaked out to an external processor residing on the Internet, which is undesirable in terms of security.